Automatic heat-controller for steam-boiler furnaces.



Patented lan. i4, |9032.

D. H. BARBIN & E. MGLEAN. AUTUMATIG HEATl CONTROLLER FRl STF-LAMy BUILER FURNAC'ES.

(Appication filed Jpn. 8, 1898.)

3 Sheets-Sheet l.

wz' Noams PE-rzns co, moro-Limo, wAsHxNnmN, rz` c Patented Jan. I4, |902.

No. 690,93l.

D. H. BARBIN & E. MCLEAN. AUTOMATIC HEAT CONTROLLER FOB STEAMBUILER FURNACES.

(Application filed Jam. 8, 1898.)

3 Sheets--Sheet 2.

lNvENToHs" (No Nudel.)

WITNESSES:

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No. 690,931. Patented Jan. 14, |902.

n. H. uAnmN ai. McLEAn. AUTOMATIUHET -CONTROLLEB lFOliV STEAM BOILER vFURNAGES.

(Application led Jan. 8, 1898.) (No Model.) 3 Sheets-Sheet 3.

: .22g/*Mages Y MZ Wm "5M/ums @MWWMWW lilni'rnn Strains DAVID DARRIN, OF ORANFORD, NEW JERSEY, AND EMBURY MCLEAN Farrar union,

OF BROOKLYN, NEX/V YORK; SAID DARRIN ASSIGNOR TO SAID MCLEAN.

AUTOMATIC HEAT-CONTROLLER FOR STEAM-BOILER FURNACES.

SPEGIFECATION' forming part of Letters Patent No. 690,931, dated January 14, 1902.

Application filed January 8, 1898. Serial No. 666,108. LNo model.)

To @ZZ whom t may concern,.-

Be it known that we, DAVID H. DARRIN, of Cranford, Union county, New Jersey, and EMBURY MGLEAN, of Brooklyn, borough of Kings, New York, have invented certain new and usefullmprovements in Automatic Heat- Oontrollers for Steam-Boiler Furnaces Supplied with Forced-Air Draft, of which the following is a specification.

rlhis invention has for its object to increase the efficiency of forced-air-draft apparatus and improve the results of heatingfurnaces provided with such apparatus; and to this end the invention contemplatesa special organization of apparatus hereinafter set forth for effecting simultaneous regulation of the forced-air supply and of the discharge of the gaseous products of combustion through the stack or [lue of the furnace, thereby causing to be maintained in the furnace a practically-uniform pressure under all conditions of the rate of combustion of the fuel and the consequent retention of the heated gases in the furnace or boiler setting and the prevention of uncalled-for air entering the furnace, thus insuring the most economical results from the burning ofsuch fuel.

Heretofore forced-air-supplying apparatus for furnaces of boilers, dre., have been devised in one class of which the blast of air has been regulated by the steam from the boiler heated by the furnace acting through a controlling device to regulate the supply of the active agent actuating the motor which operates the fan or blower, the various devices constituting the apparatus being so arranged and operated that the fan or blower does not entirely cease operating when the maximum pressure in the boiler is reached, but at such times supplies sufficient air to the furnace beneath the grate-bars as will prevent undue burning away of the gratebars and to keep the fuel alight. While the use of such apparatus produces goed results, yet the best results are far from being attained,for the reason that when the fan is supplying the minimum amount of air to the fur nace the natural draft of the stack causes an attenuation of the gases in the furnace above the fuel, thus increasing their flow and to a considerable extent drawing in cold air above the fuel, which chills the products of combustion, contracts the plates and tubes, and cools the boiler and setting. It is also common practice to automatically regulate the stack or flue opening by damperregulators controlled by the pressure of the steam in the boiler, and special regulators have been devised actuated by fluid-pressure from an independent source in such manner as to positively act on the motordevice of the controller to close it and to release the same to allow the controller to open by a free dis' charge of the fluid from such motor device.

Now'in carrying out the invention We employ a forced air draft apparatus and a damper controlling device having the general characteristics above set forth, combining the two in such manner and simultaneously regulating o1' controlling them through the medium of a fluid under pressure supplied from an independent source, so as to cause a closing of the damper in the flue or stack at the same time and in conformity with the reduction of air supplied to the furnace by the forced draft apparatus, thus confining the hot gases in the furnace or boiler setting and maintaining a substantially uniform pressure therein and preventing air being drawn into the furnace above the fuel in excess of that properly delivered below the fuel by the fan at its lower speed, as Would occur if the stack were left fully open for its normal natural draft to act.

To more fully describe the invention, reference will n'oW be had to the accompanying drawings, forming part of this specification, in which-- Figure l is a View showing all of the apparatns and devices suitable for the practical carrying outof the invention conventionally arranged to more'clearly show their relation to one another. Fig. 2 is an enlarged View showing the controlling devices in section; Fig. 3, a vertical section of the controllingmedium regulator or governor; Fig. 3, a section therethrough on the line 3 3 of Fig. 3, and Fig. 4 a front view of the governor I with the front plate removed.

The general features of the invention,with out going into detailsof construction of tho IOO various parts and devices, will be first described by :reference to Fig. l, which illustrates the application of the invention to a steam-boiler and its furnace. The air for the combustion of the fuel in the furnace is supplied by the blowerA, through the conduit A', to the ash-pit or under side of the furnace B, all parts of which are properly closed to exclude the entrance of air excepting that supplied by the blower. A damper A2 is shown at the mouth of the conduit A', arranged so as to deflect the air and distribute it to all parts of the grate-bars. rlhe boiler B' and smoke-stack B2 are of the ordinary construction. The main steam-pipe B3 supplies steam through the pipe C to the motor C', connected to the blower A, to produce the forced-air draft. This pipe C is provided with a pressure-regulator or reducing-valve D, set to impart to the motor C' the desired speed to provide a maximum amount of air to the furnace B, and it is also provided with the controller E, actuated to entirely cut off the steam passing through the pipe C when the normal working pressure of the steam in the boiler is exceeded; butat such times sufficientsteam passes tothe motor C' to maintain it in motion and'keep up a small supply of air to the furnace through the by-pass pipe C2, which is provided with a pressure-regulator or reducing-valve F, which allows just enough steam to pass to the motor C' to keep it uniformly moving at its reduced speed.

The damper G in smoke-stack B2 is connected by the levers G' to the damper-controller H, which when positively actuated by the fluid-controlling mediumtends to close the damper against the action of the weight G2, which tends to open the damper.

The regulator or governor I of the iiuidcontrolling medium is at its .lower end connected by the pipe I' to the steam-space of the boiler B' at l2. The upper end of this governor I connects with the source of the controlling fiuid-pressure vby the pipe J, which source is here represented as an air-compressor J', operated to supply and maintain a charge of compressed air in the reservoir J2. A pipe K, extending from the upper part of governor I, connects with and is common to both the forced-air-draft-motor controller E and the damper-controller H.

As the details of constructionof the various devices so far here described form no part of the invention, we will, before entering into such details, briefly state the functions of the different devices in setting forth their coperation to prod uce the desirable results sought by the invention. Now assuming that the forced-air-draft motor C' has been running at its maximum speed, steam being supplied thereto mainly through the pipe C, and that the steam in the boiler has slightly exceeded its normal working or attained its maximum pressure, the steam at such increased pressure will by the pipe I' act on the governor I and allow air to flow between the pipes J and K from the reservoir J2, said air by its pressure thus simultaneously operating the controller E of the air-draft motor C' to cut off the main supply of steam to said motor and the consequent main supply of air to the furnace and the damper-controller H to close the damper G, as shown in the drawings, to such an extent as will prevent the escape of the heated gases from the furnace and boiler setting beyond what is necessary to maintain the normal and uniform pressure in the furnace now being supplied with the greatly-reduced volume of air. As soon as the steam falls to its normal working pressure it ceases to operatively act on the governor I, communication between the pipes Jand K being now closed and the pipe K vented or opened to the atmosphere, thereby releasing the controllers E and H from the controlling fluidpressure and again permitting the full Working quantity of steam to pass to the motor C' and the Weight G' to again open the damper G. The venting of the pipe K may be such as to allow the compressed air to escape slowly from the controllers E and H, so that the speed of the motor C' is gradually increased and the damper G gradually opened, while their reverse actions, due to increase of pressure in the boiler through the operation of the governor I, are much quicker.

To more fully explain the construction and operation of the various devices employed in this combined forced -air-draft and damper regulator,such suitable devices are illustrated on an enlarged scale and in section at Figs. 2 and The regulator or governor of the controlling medium comprises a chamber L, in communication with the boiler by the pipe I' and covered by a fiexible diaphragm L2, against which bearsa lever L', pressed against the diaphragm by an adjustable spring L2; another chamber M in communication with the controlling air-supply pipe J through a fine orifice M3 and having an outlet M4 somewhat larger than the inlet-orifice; a diaphragm M', closing this chamber; a spring-actuated lever M2, provided with a valve-seat to close the outlet-orifice M4 of the chamber M; a pivoted arm N, connected to the diaphragm M'; a supply and vent valve O,actuated by a lever N', carried by the arm N, so as to close communication between the air-pipes J and K by seatingagainst the valve-seat O' and to close the air-vent of the pipe K, which is around the free-fitting stem of the valve, by seating against the valve-seat O2 when it moves away from the seat O', as shown at Fig. 2. The free end of the arm N has a projection N2, straddling a post N2, projecting laterally from the side of the casing and provided with two adjustable stop-nuts, between which the projection N2 plays, whereby the extent of movement in either direction of the arm N and diaphragm M' is determined. The lever N', carried by the arm N, is a springactuated toggle-lever and is pivoted near its upper end to the arm N and has its lower end connected ILO IIO

with that arm by a slot-and-pin connection N4. The eXtreme upper end of lever N works in a groove in the stein of the valve O. The tension of the spring L3, bearing on the lever L', operated by the diaphragm L, is adjusted by a screw L4, passing through the center of dial L and provided with an index-pointer L6 and a thumb-piece L7.

The two regulating or reduction valves D and F are of the ordinary construction, and

' their functions in the steam-pipe C and bypass C2 will be readily understood from the foregoing statement. The same may be said of the controllers E and H, they being ordinary diaphragm fluid-motors, the diaphragm of the controller E being attached to the valve E in such manner as to close it when the diaphragm is inflated, said valve being opened by the spring E2 when the controller is relieved of the air pressure. The diaphragm H' of the controller II is connected to the damper G through the system of levers Gr in such manner that its inflation tends to close the damper against the opening action of the Weight G2. The diaphragme of these controllers Eland H are shown inflated at Fig. 2, the parts of the governor I being shown at Fig. 3 iu position assu nied by them after the boilerpressure has fallen sufciently for the springactuated lever L to recede from the lever M2, which now closes the discharge or vent orice M4 of the chamber M, allowing air from the pipe J to accumulate in the chamber M to force the diaphragm M outwardly, and so close the valve O onto the seat O' and open the vent around its stem by leaving the seat O2. The air or controlling medium is thus cut off from the controllers E and II, and the air that is in these controllers is now free to gradually escape by the vent around the stem of the valve O. In this operation the parts effect the movement of the valve O in the following manner: The pressure under the diaphragm M moves the arm outwardly, and the upper end of toggle-lever N being held against movement by the stem of valve O,

which now bears on its seat O2, the joint in the toggle-lever is moved beyond its center line, and its spring then acts to instantly move the lever into the position shown in Fig. 3, there transferring the val-ve O from the seat O2 to the seat O. The reverse of this operation occurs, when the pressure under diaphragm M is relieved by the opening of the vent M4. When the steam again rises sufficiently to force out the lever L', the seat on the lever M2 is moved away from the discharge-orifice of the chamber M, allowing the air to escape therefrom faster than it enters therein through the smaller inlet-orifice. The diaphragm then collapsing causes the valve to close the vent around its stem and allows air to pass from the pipe J to the controllers E and H through the pipe K, as shown at Fig. 3.

'y in Fig. 3 indicates an aperture in the casing constituting a vent for the compressed air that may be discharged within the casing.

Gther forms of controllers and governing devices than those here shown may be used, and also any source of fluid-pressure other than that illustrated at J J2 may be utilized as the controlling medium to produce the desired result of the invention, so we do not limit ourselves to the combination of the particular devices here shown.

IVe claim as our inventionl. An automatic apparatus for controlling the heat of a steam-boiler furnace, consisting of a blower for supplying a forced-air draft to the furnace, a motor for operating the blower, adamperin the flue or stack, two coutrollers for regulating respectively the forceddraft motor and the damper, and a single regulator or governor actuated by steam from the boiler to simultaneously set in action the forceddraft motor and damper controllers,-

of a blower for supplying a forced-air draft 9 to the furnace, a motor for operating the blower, a damper in the fine or stack, two controllers for regulating respectively the forced-draft motor and the damper, a fluidcontrolling medium from an independent source for actuating the controllers, and a single regulator or governor actuated by steam from the boiler to permit said fluid medium to simultaneously cause the action of said controllers, whereby when the boiler-pressure rises the damper is closed and the blowermotor checked, and when the pressure falls the damper is opened and the blower-motor permitted to resume its normal speed..

In testimony whereof we have hereunto subscribed our names.

DAVID H. DARRIN.

EMBURY MOLEAN.

X'Vtnesses:

FRANK S. OBER, ALFRED SHEDLoon.

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